I set to work copying German code settings.

When I’d finished, I folded the exercise book and the copied charts over the keyboard of the coding machine and closed the lid. I put it back in the wardrobe, where it was safe enough hidden beneath Johanna von Arnim’s old evening clothes. Now all we had to do was wait for Ellen to come back to collect the leaflets for Jamie.

“Why don’t you play your flute for me again?” Jane suggested.

A different idea came to me all of a sudden.

“Couldn’t you teach me Morse code?” I asked.

She turned over her upside-down teacup and lifted the teapot to pour herself some stewed, cold tea. She was surprisingly unfussy about her tea.

“What makes you think I can teach you Morse code?” she asked.

“You were a telegraphist,” I said. “And if I learned now, I could join the forces, perhaps, when I’m older. I only left school two months ago—I feel like I should still be learning things. And… it might be useful.”

“It might be,” Jane agreed.

I screwed the sections of my flute together.

“I thought I could learn it and practice at the same time,” I said, and held the flute to my lips. I drew in a deep breath, as if I were about to dive into cold water. Then I held down my thumb and opposite pinkie and the first two fingers of my left hand and played an A.

“Oh, of course!” said Jane.

She sang an A.

“Tra-laaaa.”

Dot-dash. Short-long.

I played another A, tra-la, quaver and crotchet, tra-la, tra-la, tra-la.

Jane’s amazing near-contralto swooped up a step to a B. “Traaaa-lalala.”

I echoed her on the flute. AB, AB, tra-lahh, tra-lalala, tra-lahh, tra-lalala.

And on up the A-minor scale, getting quicker and surer all the time, until by G we were both breathless and had to stop because Jane started to mix up notes to test me, and I trilled them staccato back to her like sleet against window glass, and we laughed so hard we couldn’t sing nor play.

And in one afternoon I learned almost a third of the alphabet in Morse code.